From 22f703cab05b7cd368f4de9e03991b7664dc5022 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?J=C3=B6rg=20Frings-F=C3=BCrst?= Date: Mon, 1 Sep 2014 13:56:46 +0200 Subject: Initial import of argyll version 1.5.1-8 --- tiff/html/man/TIFFRGBAImage.3tiff.html | 319 +++++++++++++++++++++++++++++++++ 1 file changed, 319 insertions(+) create mode 100644 tiff/html/man/TIFFRGBAImage.3tiff.html (limited to 'tiff/html/man/TIFFRGBAImage.3tiff.html') diff --git a/tiff/html/man/TIFFRGBAImage.3tiff.html b/tiff/html/man/TIFFRGBAImage.3tiff.html new file mode 100644 index 0000000..7bbee0f --- /dev/null +++ b/tiff/html/man/TIFFRGBAImage.3tiff.html @@ -0,0 +1,319 @@ + + + + + + +TIFFRGBAImage + + + +

TIFFRGBAImage

+NAME
+SYNOPSIS
+DESCRIPTION
+ALTERNATE RASTER FORMATS
+SIMULTANEOUS RASTER STORE AND DISPLAY
+SUPPORTING ADDITIONAL TIFF FORMATS
+NOTES
+RETURN VALUES
+DIAGNOSTICS
+SEE ALSO
+ +

+ +

NAME

+ + + + + +

TIFFRGBAImageOK, TIFFRGBAImageBegin, TIFFRGBAImageGet, +TIFFRGBAImageEnd − read and decode an image into a +raster

+ +

SYNOPSIS

+ + + + + +

#include <tiffio.h>

+ +

typedef unsigned char TIFFRGBValue; typedef struct +_TIFFRGBAImage TIFFRGBAImage;

+ +

int TIFFRGBAImageOK(TIFF *tif, char +emsg[1024])
+int TIFFRGBAImageBegin(TIFFRGBAImage *img, +TIFF* tif, int stopOnError, +char emsg[1024])
+int TIFFRGBAImageGet(TIFFRGBAImage *img, +uint32* raster, uint32 width , +uint32 height)
+void TIFFRGBAImageEnd(TIFFRGBAImage +*img)

+ +

DESCRIPTION

+ + + + + +

The routines described here provide a high-level +interface through which TIFF images may be +read into memory. Images may be strip- or tile-based and +have a variety of different characteristics: bits/sample, +samples/pixel, photometric, etc. Decoding state is +encapsulated in a TIFFRGBAImage structure making it +possible to capture state for multiple images and quickly +switch between them. The target raster format can be +customized to a particular application’s needs by +installing custom routines that manipulate image data +according to application requirements.

+ +

The default usage for these routines is: check if an +image can be processed using TIFFRGBAImageOK, +construct a decoder state block using +TIFFRGBAImageBegin, read and decode an image into a +target raster using TIFFRGBAImageGet, and then +release resources using TIFFRGBAImageEnd. +TIFFRGBAImageGet can be called multiple times to +decode an image using different state parameters. If +multiple images are to be displayed and there is not enough +space for each of the decoded rasters, multiple state blocks +can be managed and then calls can be made to +TIFFRGBAImageGet as needed to display an image.

+ +

The generated raster is assumed to be an array of +width times height 32-bit entries, where +width must be less than or equal to the width of the +image (height may be any non-zero size). If the +raster dimensions are smaller than the image, the image data +is cropped to the raster bounds. If the raster height is +greater than that of the image, then the image data are +placed in the lower part of the raster. (Note that the +raster is assume to be organized such that the pixel at +location (x,y) is +raster[y*width+x]; with the +raster origin in the lower-left hand corner.)

+ +

Raster pixels are 8-bit packed red, green, blue, alpha +samples. The macros TIFFGetR, TIFFGetG, +TIFFGetB, and TIFFGetA should be used to +access individual samples. Images without Associated Alpha +matting information have a constant Alpha of 1.0 (255).

+ +

TIFFRGBAImageGet converts non-8-bit images by +scaling sample values. Palette, grayscale, bilevel, +CMYK , and YCbCr images are converted to +RGB transparently. Raster pixels are returned +uncorrected by any colorimetry information present in the +directory.

+ +

The parameter stopOnError specifies how to act if +an error is encountered while reading the image. If +stopOnError is non-zero, then an error will terminate +the operation; otherwise TIFFRGBAImageGet will +continue processing data until all the possible data in the +image have been requested.

+ +

ALTERNATE RASTER FORMATS

+ + + + + +

To use the core support for reading and processing +TIFF images, but write the resulting raster +data in a different format one need only override the +‘‘put methods’’ used to store +raster data. These methods are are defined in the +TIFFRGBAImage structure and initially setup by +TIFFRGBAImageBegin to point to routines that pack +raster data in the default ABGR pixel format. +Two different routines are used according to the physical +organization of the image data in the file: +PlanarConfiguration=1 (packed samples), and +PlanarConfiguration=2 (separated samples). Note that +this mechanism can be used to transform the data before +storing it in the raster. For example one can convert data +to colormap indices for display on a colormap display.

+ +

SIMULTANEOUS RASTER STORE AND DISPLAY

+ + + + + +

It is simple to display an image as it is being read into +memory by overriding the put methods as described above for +supporting alternate raster formats. Simply keep a reference +to the default put methods setup by +TIFFRGBAImageBegin and then invoke them before or +after each display operation. For example, the +tiffgt(1) utility uses the following put method to +update the display as the raster is being filled:

+ +

static void
+putContigAndDraw(TIFFRGBAImage* img, uint32* raster,
+    uint32 x, uint32 y, uint32 w, uint32 h,
+    int32 fromskew, int32 toskew,
+    unsigned char* cp)
+{
+    (*putContig)(img, raster, x, y, w, h, fromskew, toskew, cp);
+    if (x+w == width) {
+     w = width;
+     if (img->orientation == ORIENTATION_TOPLEFT)
+         lrectwrite(0, y-(h-1), w-1, y, raster-x-(h-1)*w);
+     else
+         lrectwrite(0, y, w-1, y+h-1, raster);
+    }
+}
+

+ +

(the original routine provided by the library is saved in +the variable putContig.)

+ +

SUPPORTING ADDITIONAL TIFF FORMATS

+ + + + + +

The TIFFRGBAImage routines support the most +commonly encountered flavors of TIFF. It is +possible to extend this support by overriding the +‘‘get method’’ invoked by +TIFFRGBAImageGet to read TIFF image +data. Details of doing this are a bit involved, it is best +to make a copy of an existing get method and modify it to +suit the needs of an application.

+ +

NOTES

+ + + + + +

Samples must be either 1, 2, 4, 8, or 16 bits. +Colorimetric samples/pixel must be either 1, 3, or 4 (i.e. +SamplesPerPixel minus ExtraSamples).

+ +

Palette image colormaps that appear to be incorrectly +written as 8-bit values are automatically scaled to +16-bits.

+ +

RETURN VALUES

+ + + + + +

All routines return 1 if the operation was successful. +Otherwise, 0 is returned if an error was encountered and +stopOnError is zero.

+ +

DIAGNOSTICS

+ + + + + +

All error messages are directed to the +TIFFError(3TIFF) routine.

+ +

Sorry, can not handle %d-bit pictures. The image +had BitsPerSample other than 1, 2, 4, 8, or 16.

+ +

Sorry, can not handle %d-channel images. The image +had SamplesPerPixel other than 1, 3, or 4.

+ +

Missing needed "PhotometricInterpretation" +tag. The image did not have a tag that describes how to +display the data.

+ +

No "PhotometricInterpretation" tag, assuming +RGB. The image was missing a tag that describes how to +display it, but because it has 3 or 4 samples/pixel, it is +assumed to be RGB.

+ +

No "PhotometricInterpretation" tag, assuming +min-is-black. The image was missing a tag that describes +how to display it, but because it has 1 sample/pixel, it is +assumed to be a grayscale or bilevel image.

+ +

No space for photometric conversion table. There +was insufficient memory for a table used to convert image +samples to 8-bit RGB.

+ +

Missing required "Colormap" tag. A +Palette image did not have a required Colormap +tag.

+ +

No space for tile buffer. There was insufficient +memory to allocate an i/o buffer.

+ +

No space for strip buffer. There was insufficient +memory to allocate an i/o buffer.

+ +

Can not handle format. The image has a format +(combination of BitsPerSample, +SamplesPerPixel, and +PhotometricInterpretation) that can not be +handled.

+ +

No space for B&W mapping table. There was +insufficient memory to allocate a table used to map +grayscale data to RGB.

+ +

No space for Palette mapping table. There was +insufficient memory to allocate a table used to map data to +8-bit RGB.

+ +